1. Field of the Invention
The invention relates to an exchange for the computer-controlled switching of digital time-interleaved data incoming in cyclically repeated frames in a number of input lines equal to the number of output lines via a switching matrix, which comprises
at the input end a number of cyclically operated change-over switches in parallel which distribute the input data of the input lines frame-sequentially and cyclically over an identical number of input intermediate lines,
a central stage connected to the input-intermediate lines and including data stores, in which the data paths to be switched are determined and which applies the data to a number of output intermediate lines equal to the number of input intermediate lines,
at the output end, further cyclically operated change-over switches in parallel which distribute the transmitted data frame-sequentially and cyclically over the output lines on which the transmitted data appear.
2. Description of the Related Art
Such an exchange is disclosed in European Patent EP-OS No. 116 386 and the corresponding publication "IEEE International Conference on Comm. 1984", Volume 1, pages 299-302. Such an exchange behaves as a one-stage switching matrix in which consequently no path search is required, and, in addition, is of the non-blocking type. This known principle can also be used for larger numbers of channels or input lines. The central stage, that is to say the actual switching stage, is then a time-switching stage which includes a one-bit store for each channel. In addition to these data stores a large number of switches is however required, which together represent quite a considerable cost.